Pctel, Inc.

Pctel Maryland, Inc.

Vikash Srivastava

Amir Soltanian

Meng Chen

Mirjana Peric

A method and apparatus are provided for decoding a wireless signal from a set of samples with an embedded training sequence. The method includes the steps of determining a first frequency offset from the samples where the first frequency offset is assumed to be less than a Nyquist frequency of the training sequence and calculating a first carrier to interference ratio based upon the first frequency offset. The method further includes the steps of determining a second frequency offset from the samples by subtracting an absolute value of the first frequency offset from an integer multiple of the Nyquist frequency and giving the second frequency offset a sign opposite that of the first frequency offset, calculating a second carrier to interference ratio based upon the second frequency offset and selecting one of the first and second frequency offsets based upon a relative values of the calculated carrier to interference ratios.

Iterative pilot-aided frequency offset estimation and C/I measurement for TDMA signal with offset larger than nyquist frequency of the reference symbol rate

An apparatus (and corresponding methodology) for discovering beacon signals in a spread spectrum radio communication system is selectively operable in one of two modes. The first mode employs a local reference timing signal, while the second mode employs a GPS-derived reference timing signal. Preferably, the first mode identifies a baseline beacon signal that satisfies a constraint based upon time delays for detected beacon signals which are indicative of the relative distance of the transmitting base stations, thus providing selection of a baseline beacon signal that originates from a relatively close base station. The index of the baseline beacon signal is recovered and then used together with relative timing derived from the local reference timing signal to assign indices to other detected beacon signals. In another aspect, control means is provided for selectively switching between the first and second modes in accordance with a plurality of user-selectable modes, which preferably include a GPS-priority mode (whereby the control means automatically switches between the first and second modes based upon GPS signal receive status) and an Indoor mode (whereby the control means operates in the first mode irrespective of GPS signal receive status).

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Boyds, MD, United States of America

Vikash Srivastava